4 Answers
4

remap is an option that makes mappings work recursively. By default it is on and I'd recommend you leave it that way. The rest are mapping commands, described below:

:map and :noremap are recursive and non-recursive versions of the various mapping commands. What that means is that if you do:

:map j gg
:map Q j
:noremap W j

j will be mapped to gg. Q will also be mapped to gg, because j will be expanded for the recursive mapping. W will be mapped to j (and not to gg) because j will not be expanded for the non-recursive mapping.

Now remember that Vim is a modal editor. It has a normal mode, visual mode and other modes.

For each of these sets of mappings, there is a mapping that works in normal, visual, select and operator modes (:map and :noremap), one that works in normal mode (:nmap and :nnoremap), one in visual mode (:vmap and :vnoremap) and so on.

Thanks for your answer! Also, when is recursive used, and when is non-recursive used?
– ChetanSep 29 '10 at 22:35

13

@Chetan: It depends what you want to achieve. I tend to use non-recursive more often, but if you've defined a relatively complicated mapping using non-recursive and what another mapping that does everything the first mapping does and more, it can be easier to use a recursive mapping that includes the original one rather than retyping the whole of the non-recursive one again (particularly if you then need to tweak the original one).
– DrAlSep 30 '10 at 7:02

102

A well written answer, I wish ViM documentation on these was this clear! :-)
– Ashwin NanjappaNov 24 '10 at 3:19

5

I had assumes noremap to be some opposite of map. I mean something which removes a mapping. Thanks for the answer. It clarified me
– Pavan ManjunathMar 14 '12 at 9:07

4

It isn't that important for the majority of use cases, but it should be noted that :map, etc. don't work in all modes, exactly, just all the common ones (specifically, normal mode, visual mode, select mode, and operator-pending mode). If you want a mapping to work in insert, command-line, or lang-arg mode, you need to use :map!, etc. (Source: vimdoc.sourceforge.net/htmldoc/map.html#map-overview)
– Ken BellowsJun 26 '13 at 14:00

I think the Vim documentation should've explained the meaning behind the naming of these commands. Just telling you what they do doesn't help you remember the names.

map is the "root" of all recursive mapping commands. The root form applies to "normal", "visual+select", and "operator-pending" modes. (I'm using the term "root" as in linguistics.)

noremap is the "root" of all non-recursive mapping commands. The root form applies to the same modes as map. (Think of the nore prefix to mean "non-recursive".)

(Note that there are also the ! modes like map! that apply to insert & command-line.)

See below for what "recursive" means in this context.

Prepending a mode letter like n modify the modes the mapping works in. It can choose a subset of the list of applicable modes (e.g. only "visual"), or choose other modes that map wouldn't apply to (e.g. "insert").

Use help map-modes will show you a few tables that explain how to control which modes the mapping applies to.

"Recursive" means that the mapping is expanded to a result, then the result is expanded to another result, and so on.

The expansion stops when one of these is true:

the result is no longer mapped to anything else.

a non-recursive mapping has been applied (i.e. the "noremap" [or one of its ilk] is the final expansion).

At that point, Vim's default "meaning" of the final result is applied/executed.

"Non-recursive" means the mapping is only expanded once, and that result is applied/executed.

Example:

nmap K H
nnoremap H G
nnoremap G gg

The above causes K to expand to H, then H to expand to G and stop. It stops because of the nnoremap, which expands and stops immediately. The meaning of G will be executed (i.e. "jump to last line"). At most one non-recursive mapping will ever be applied in an expansion chain (it would be the last expansion to happen).

The mapping of G to gg only applies if you press G, but not if you press K. This mapping doesn't affect pressing K regardless of whether G was mapped recursively or not, since it's line 2 that causes the expansion of K to stop, so line 3 wouldn't be used.

Careful !! command mode is another historical name for normal mode viz. chapt 5 vimdoc.sourceforge.net/htmldoc/intro.html#vim-modes-intro). The abbreviation 'c' is for 'command-line'. In other words, by default: map! lhs rhsrecursively maps lhs to rhs for insert + command-LINE modes. That is unless the remap default option is explicitely disabled with set noremap[!] in ~/.vimrc. In that case mapping would not be recursive (not advisable).
– CbhiheAug 15 '15 at 19:00